We describe a new prototype task, emergency handling, for multi-robot coordination. The experiments reported here measure the eects of individualism and opportunism in a physically-implemented multi-robot system. We use sound at multiple frequencies to simulate emergencies by producing several locally-sensable gradients in the environment. Our results show that opportunism affords a significant performance improvement over individualism. Our experiments also demonstrate the viability of sound for producing detectable local gradients in the environment.